Mechanical horn.



E. J. WILLIS.

MECHANICAL HORN.

APPLICATION FILED 2mm, 1912.

Patented Sept. 8, 1914;-

UNITED STATES PATENT OFFICE.

ERNEST J'. WILLIS, OF NEW YORK, N. Y., ASSIGNOR, BY MESNE ASSIGNMENTS,TO

LOVELL-MQCONNELL MANUFACTURING COMPANY, A CORPORATION OF DELA- WARE.

MECHANICAL HORN.

To all whom it may concern:

Be it known that I, ERNES" J. IVILLIS, a subject of the King of theUnited Kingdom of Great Britain and Ireland, residing at the borough ofManhattan, in the city, county, and State of New York, have inventedcertain new and useful Improvements in Mechanical Horns, of which thefollowing is a specification, reference being had therein to theaccompanying drawings, which form a part thereof.

My invention relates to mechanical horns of that type in which a strikermember preferably'in the form of a rotary cam imparts vibrations to adiaphragm to generate the sound waves.

In'carrying out my invention, I transmit the impacts, blows or forcedthrusts from the rotor to the diaphragm by means of an interposed levermember and as an important feature of my invention, I make that portionof said member between the point'of its engagement with the strikermember and the end engaging the diaphragm, stiffened or reinforced so asto avoid any loss of the power applied thereto through elasticity atthis point.

I preferably employ a small electrical motor as the source of power, andone feature of my invention involves the mounting'of this motor so as toavoid any loss of 'alinement of the shaft carrying the striker'memher,while admitting of the accurate adj ust ment of said member inassembling the de vice. And a still further object is to provide a hornof this character which will be simple in design and inexpensive toproduce. Referring to the drawings: Figure 1 is a longitudinal sectionof a horn embodying my invention; Fig. 2 is a section on the line 2-2 ofFig. 1; Figs. 3, 4 and 5 are similar to Fig. 2, showing modified formsof impact members.

Like letters refer to like parts throughout the several views.

In the embodiment of my invention shown in the drawings, a/indicates afront diaphragm casing section provided with an opening a communicatingwith an amplitier 7). Secured to the casing section a is a reardiaphragm casing section 0 having thereon a plurality of lugs or flanges(Z e adapted to support the motor f. The lugs Specification of LettersPatent.

Application filed February 6, 1912.

Patented Sept. 8, 1914.

Serial No. 675,836.

' will be clamped in place between these two detachable sections. Thecasing a has a cylindrical peripheral flange a adapted to inclose theedge of the diaphragm k and secure it and the gaskets h and k inposition relative to said casing. The diaphragm it as shown presents anuninterrupted plane, no stud being used centrally thereof, thuspreserving the entire strength of the diaphragm and avoiding theweakening thereof in a manner to impart thereto a tendency to cup;Inclesing the motor f is a cupshaped housing 2' carrying the electricalcon ta-cts which are adapted to be automatically coupled to the motorupon the application of same to the casing. This housing is secured bymeans of screws is to the section 0.

Carried by the shaft Z of the motor 7 is a rotor or cam constituting astriker member preferably formed of a sheet metal plate m having thereona plurality of contact surfaces or cam faces m, these surfaces beingraised above the plane of said plate and being spaced apart sufiicientlyto afford ample clearance between Succeeding contacts to permit such aninterval of time between the successive blows imparted by said strikermember as will allow the diaphragm to havethe full amount of reflexaction between the impacts flexing same. The height of the contacts orcam faces m. is greater than the amount of displacement of the diaphragmupon the reflex action thereof. Instead of [so mounting the rotor thatthe cam faces thereon will directly engage with the diaphragm itself, Imount between the rotor m and the diaphragm h a flxible'diaphragmvibrating member n adapted to be forced by the impact from the cam facesof the rotor and en gage with the diaphragm to forcibly dis- (Z e areprovided with elongated slots to 1 place the latter, upon receiving eachimios pact and thus set said diaphragm into rapid vibration to developsound waves of the desired frequency and intensity. In the preferredform, this diaphragm vibrating member is in the form of a. flat strip ofhighly tempered spring metal extending radially of the diaphragm withits outer end secured adjacent to the periphery of the diaphragm and theinner end terminating adjacent to the center of the diaphragm.

The shaft Z projects substantially axially of the diaphragm, thuspositionin the contacts m concentrically of said diaphragm andpermitting them to engage the diaphragm vibrating member intermediatethe point of support thereof and the polnt thereof adapted to engage thediaphragm, thus securing a leverage with a slightly increased quantityof movement of said memher at its point of engagement with the diaphragmover that of the point of-engagement with the said striker member. I maysecure an increase in the frequency of the flexures of the diaphragmwith each rotation of said striker member by causing said striker memberto engage the member or members alternately upon opposite sides of thecenter of said diaphragm. This may be done by giving the plate m an oddnumber of contacts m so that these contacts do not simultaneouslydeliver blows at dia-n metrically opposite points. WVhile I prefer toincrease the frequency of the'impulses imparted to the diaphragm in themanner referred to, as tending to secure a greater volume of soundwithout overloading the motor or requiring too strong a current, amember having a single point of contact and adapted to be engaged by thesaid contacts m, may be utilized if desired, and I have illustrated sucha member in the modification of the invention shown in Fig. 4,

In the form shown in Figs. 1 and2, the vibrations are imparted to thediaphragm from the rotor by two separate strips n in alinement with eachother, and each extending from the periphery to the center of thediaphragm. At their outer ends they may beriveted to the casing section0 and the inner ends thereof may be spaced :1 very slight distanceapart. Formed up from these strips at the free end thereof, are studs nadapted to having forcing engagement with the diaphragm and at the sametime permit the other portions of said member to be spaced away from thediaphragm sufficiently to aviod interference therewith. In the .specificembodiment illustrated, the studs 11 when thus assembled, are spacedaway from the diaphragm in order. to secure higher efiiciency in theoperation of the device. Each said stud also has formed up therein, butupon the face oppositeto the stud n, a contact 02 positioned within theoperative range of the contacts m, said contacts n being spaced awayfrom the studs 12. To avoid any possibility of the flexure of the memberbetween the contact n and the stud m, I form in said strip a fillet orbead, extending from said stud to said contact, said fillet being a mereextension of the contact 11 This fillet or bead stiffens the memberbetween the point of engagement of the striker member therewith and thestud 02. By this construction, I am not only enabled to construct thediaphragm vibrating member and the studs and contacts thereon of asingle strip of metal, but also to provide a diaphragm vibrating memberwhich is normally spaced away from the diaphragm throughout its entirelength to avoid interference in the diaphragm while securing to it thathigh degree of flexibility which is desirable in a high frequency, lowpower mechanical horn of the character herein described. By duplicatingthe members a, I increase the frequency of the fiexures of the diaphragmwithout necessitating more than a duplication of the member alone. Tofacilitate the adjustment of the motor f within the lugs d e, I securethe motor in place by means of the screws 8, the heads of which bearupon the clamp plate 1' bearing upon the lug e.

In the modification shown in Fig. 3, the construction and mode ofoperation are substantially identical with that of the preferred form,with the exception however, that the member 0 instead of being'made intwo sections, as shown in the preferred form, is made of onecontinuousstrip of metal bridging the diaphragm and having a centralstud 0 formed therein and projecting toward the diaphragm, and twofillets 0 extending from said stud and terminating in contacts adaptedto be engaged by the rotor m.

In the modification shown in Fig. 4, the construction is substantiallyidentical with that shown in Fig. 3, with the exception that but asingle fillet 0 is utilized, thus reducing the frequency of thevibrations with each rotation of the striker member.

In both forms of the invention shown in Figs. 3 .and 4, the strip isstretched taut across the diaphragm, and the opposite ends thereof areriveted to the frame 0. Also in both of these forms, the interposedmember is spaced away from the diaphragm, including the stud 0 thereon.

In the modification shown in Fig. 5, of the. drawings, I provide tworadially extending members p g, which converge toward the center of thediaphragm, the outer ends of and the inner ends thereof being cupped asshown at p g to form a stud for engagement with the diaphragm. Each saidstrip p g is provided with a fillet p 9 extending from the cuppedportion p 9' thereof, for

these members being riveted to the frame 0 of the frequency of thevibrations imparted b ysaid member to the diaphragm.

The operation of the herein described device is substantially asfollows: With the closing of the circuit to the motor f, the shaft Z andthe striker member m thereon will be rapidly rotated in a fixed plane,and the contacts 112/ thereon will in sequence engage the oppositelydisposed contacts 11?, 0 p or 9 upon the interposedmember n 0 p or g,flexing this member between said contact and the point or points ofsupport of said member, and bring the stud n 0 p or 9 into engagementwith, and cause it to flex, the diaphragm h, at a point substantiallycentrally thereof, or slightly to one side of its center. The spacebetween the contact-syn will afford suflicient lead to the strikermember to cause the impact thereof with the 'contact 12, 0 p or to be inthe nature of a sharp blow, thus causing a rapid vibration of thediaphragm. The sections n, 0, p, 9, between the contact 71? 0 p or g andthe Stud 91., 0,';0' or 9, being reinforced or stiffened, sufficientrigidity is im parted to this point of the member to insure absoluterigidity thereof and thus cause the entire force of the impact of thestriker member m upon the saidmember to be trans ferred to thediaphragm. I have found in actual practice that a most effective signalcan'be secured by the construction herein described, through a flextureof the diaphragm of a sixty-fourth of an inch or less, the lowresistance due to the short interval of engagement of the contacts n 0 gand m. reducing the amperage required to run the motor to a very lowpoint. The space between the successive contacts m, coupled with the lowdegree of fiexure of the dia phrag'm, avoids a retardation of thediaphragm, and permits it upon the reflex action thereof, to pass itsnormal plane. By the multiplication of impacts a 0 p or 9 the frequencyof the impulses imparted to the diaphragm may be increased and may bethe multiple of the number of contacts 7m, and the number of opposedcontacts 71 or 9 In the preferred form of the invention, each contact mupon the striker m engages in sequency the contacts n upon the pluralityof flexible interposed impact members n, each flexible impart membermoving entirely independently of the other and acting in the same mannerupon the diaphragm.

In the form of the invention -shown in Figs..3 and 4, the bridge-likestructure of the flexible member is desirable as insuring 'said impactmember ad acent to its point of a quick return of this member to normal.

In-assemblingthe horn and attuning it, the screws 3 are releasedslightly so as to permit the entire motor to slide between the lugs dand 6 toward or from the diaphragm, and when. the desired tone has beendeveloped, said screws may be set upon the clamp plate 1' to lock themotor in this position. The location of the said lugs d and 6 will holdthe motor perfectly true so as to secure the desired alinement of themotor shaft.

It is not my intention to limit the invention to the precise details ofconstruction shown in the accompanying drawings, it being apparent thatsuch may be varied without departing from the spirit and scope of theinvention.

Having described my invention, what I claim as new and desire to haveprotected by Letters Patent, is

1. A. mechanical horn, embodying therein a flexible diaphragm, aflexible impact member supported in a fixed position relative to, and,adapted to be forced into engagement with and to flex, said diaphragm, acontact carried by said impact member adjacent to its point ofengagement with the diaphragm, a rotary striker member adapted to engagesaid contact and force said impact member into engagement with saiddiaphragm, and means actuating said striker member, said impact tweensaid contact and the point thereof engaging the diaphragm, whereby thefull force of the striker member is imparted to the diaphragm throughsaidistifi'ened portion., w

Amechanical horn, embodying therein a flexible diaphragm, a flexibleimpact member supported in a fixed position relative to, and adapted tobe forced into engagement with, and to flex, said diaphragm, a contactcarried by said impact member adjacent to its point of engagement withthe diaphragm, a rotary striker member having thereon a plurality orsequence of contacts spaced apart one from the other wherebysaid'contact carried by said impact member may pass between saidcontacts upon said striker member, and the reflex action of saiddiaphragm is permitted, and means actuating said striker member, saidimpact member being stiffened. or reinforced" between said contact andthe point thereof engaging the diaphragm, whereby the full force of thestriker member is imparted to the diaphragm through said stiffenedportion.

3. A. mechanical horn, embodying therein a flexible diaphragm presentinga plane surface adapted to be engaged by an impact member, a flexibleimpact member supported in a fixed position relative" to, and adapted tobe forced into engagement with and to flex, said diaphragm, a contactcarried by .member being stiffened or reinforced beactuating saidstriker member, said impactmember being stiffened or reinforced betweensanl contact and the point thereof engaging the diaphragm, whereby thefull force of the striker member is imparted to the diaphragm throughthe said stifiened portion.

4-. A mechanical horn, embodying therein a flexible diaphragm, a rotarystriker member, a flexible impact member between said striker member andsaid diaphragm and adapted to be forced into engagement with saiddiaphragm by said striker member, said striker member acting" upon saidimpact member eccentrica-lly of said diaphragm, and said impact memberbetween the point of engagement of the striker member therewith, and thepoint of its engagement with the diaphragm, being stifiened orreinforced, whereby the full force of the blow delivered by said strikermember is imparted to the diaphragm. j

A mechanical horn embodying therein a diaphragm, a cam rotor disposedadjacent thereto and means for effecting vibration of said diaphragmupon the rotation of said rotor, said means including a flexible mem:her having operative engagement with the diaphragm at the center of thelatter and one end supported adjacent the periphery of the diaphragm,and a contact carried by said member adjacent to its point of engagementwith the diaphragm, said member bein stiftoned or. reinforced betweensaid contadt and the point thereof engaging the diaphragm. 6. Avmechanical horn embodying therein a diaphragm, a cam rotor disposedadjacent thereto and means for effecting vibration ofsaid diaphragm uponthe rotation of said rotor, said means including a sheet metal stripextending radially of the diaphragm substantially parallel thereto andhaving operative engagement with the diaphragm at the central portion ofthe latter, said memher having a contact adapted to be engaged bv saidcam rotor, and having a'stifiening or reinforcing element between saidcontact and the point of said member engaging the diaphragm, i

T. A mechanical horn embodying therein a diaphragm, a flexible elongatedmember extending substantially radially and having thereto and rotatableabout an axis substantially at right angles to said diaphragm at thecenter of the latter, and means for effeeling vibration of saiddiaphragm u on the rotation of said cam, said means inc uding a sheetmetal strip extending radially of the diaphragm, substantially parallelthereto,'and having operative engagement with the diaphragm at thecentral portion of the latter, said member having a contact adapted tobe engaged by said cam, and spaced along the length of said member, fromthe pointof said member engaging the diaphragm, and said member having astiffening or reinforcing element extending lengthwise thereof betweensaid contact and the point or said member engaging the diaphragm. v t

.9. A signaling device including a diaphragm, an annular member havingits peripheral portion substantially rigid with the periphery of saiddiaphragm and having a large central aperture, an electric motorprojecting into said aperture and having means for vibrating saiddiaphragm, said member having a plurality of spaced flanges integraltherewith and engaging with the peripheral surface of said motor, aclamping plate upon the outer surface of one of said flanges and meansfor securing said plate rigid with said motor and with said lastmentioned flange therebetween for retaining the motor in position andpermitting of its bodily longitudinal adjustment toward and from thediaphragm.

.ln witness whereof, I have hereunto affixed my signature in thepresence of two subscribing witnesses, this 2nd day of February, 1912.

ERNEST J. WILLIS.

' Witnesses: F. T. WENTWORTH, EUGENE VVENING.

